Numerical Simulation on Forming Behavior of Magnesium Alloy at Elevated Temperatures with Experimental Verification

2013 ◽  
Vol 677 ◽  
pp. 179-182
Author(s):  
L.C. Chan ◽  
X.Z. Lu
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Experimental Test ◽  
Experimental Verification ◽  
Elevated Temperatures ◽  
Alloy Sheet ◽  
Forming Limit ◽  
Test Results ◽  
Az31b Alloy ◽  
Good Agreement

This study aimed to predict the formability of AZ31B alloy sheets at elevated temperatures by combining the experimental test with numerical simulation. Forming limit tests were performed to obtain the FLDs of the AZ31B alloy sheet at elevated temperatures of 250 °C and 300 °C. Numerical simulations of warm stamping for a camera case were established based on the forming test results. Furthermore, warm stamping experiments for the camera case were performed to validate the correction of the simulated results. The numerical results show a good agreement with the experimental observations.

scholarly journals Determining the material model at elevated temperatures with different strain rates and simulating the warm forming process for Mg alloy AZ31B sheet

2015 ◽  
Vol 18 (2) ◽  
pp. 149-158
Author(s):  
Thien Tich Truong ◽  
Long Thanh Nguyen ◽  
Binh Nguyen Thanh Vu ◽  
Hien Thai Nguyen
Keyword(s):  
Magnesium Alloy ◽  
Constitutive Equations ◽  
Elevated Temperatures ◽  
Material Model ◽  
Alloy Sheet ◽  
Strain Rates ◽  
Functional Requirements ◽  
Temperature Dependent ◽  
Forming Process ◽  
Az31b Alloy

Magnesium alloy is one of lightweight alloys has been studied more extensively today. Because weight reduction while maintaining functional requirements is one of the major goals in industries in order to save materials, energy and costs, etc. Its density is about 2/3 of aluminum and 1/4 of steel.The material used in this study is commercial AZ31B magnesium alloy sheet which includes 3% Al and 1% Zn. However, due to HCP (Hexagonal Close Packed) crystal structure, magnesium alloy has limited ductility and poor formability at room temperature. But its ductility and formability will be improved clearly at elevated temperature. From the data of tensile testing, the constitutive equations of AZ31B was approximated using the Ramgberg-Osgood model with temperature dependent parameters to fit in the experiment results in tensile test. Yield locus are also drawn in plane stress σ1- σ2 with different yield criteria such as Hill48, Drucker Prager, Logan Hosford, Y. W. Yoon 2013 and particular Barlat 2000 criteria with temperature dependent parameters. Applying these constitutive equations were determined at various temperatures and different strain rates, the finite element simulation stamping process for AZ31B alloy sheet by software PAM- STAMP 2G 2012, to verify the model materials and the constitutive equations.

Forming Limit of AZ31 Magnesium Alloy Sheet under Non-Proportional Deformation at Elevated Temperature

2013 ◽  
Vol 535-536 ◽  
pp. 292-295 ◽  
Author(s):  
Takashi Katahira ◽  
Tetsuo Naka ◽  
Masahide Kohzu ◽  
Fusahito Yoshida
Keyword(s):  
Magnesium Alloy ◽  
Plastic Strain ◽  
Elevated Temperatures ◽  
Alloy Sheet ◽  
Az31 Magnesium Alloy ◽  
Forming Limit ◽  
Plastic Strain Increment ◽  
Magnesium Alloy Sheet ◽  
Az31 Magnesium Alloy Sheet ◽  
Strain Paths

In the present work, FLDs of AZ31 magnesium alloy sheet for non-proportional strain paths were investigated by performing two-step stretch forming experiments at various forming speeds (3, 30 and 300 mm.min-1) at elevated temperatures of 150, 200 and 250°C. The forming limit strainSuperscript texts, both for proportional and non-proportional deformations, increased with temperature rise and with decreasing forming speed. A FLC after a uniaxial pre-strain lies outside of the proportional FLC for a given condition of temperature and forming speed, whereas a biaxially pre-strained FLC lies inside of the proportional FLC. It was found that the accumulated effective plastic strain and the direction of plastic strain increment at the final stage of forming are two major factors that influence the forming limits for non-proportional deformations.

Numerical Simulation of the Forming Limit of Superplastic AZ31B Magnesium Alloy Sheet

2017 ◽  
Vol 898 ◽  
pp. 159-167 ◽  
Author(s):  
Mei Juan Song ◽  
Chuan Hui Huang ◽  
Min He ◽  
Xiao Dong Luo ◽  
Bao Shun Li
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Theoretical Prediction ◽  
Damage Evolution ◽  
Alloy Sheet ◽  
Forming Limit ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Magnesium Alloy Sheet ◽  
Az31b Magnesium Alloy Sheet

Numerical simulation of superplastic forming limit of AZ31B magnesium alloy sheet was investigated. The damage evolution equation based on the law of the micro-damage evolution and statistical mechanics was derived, and damage characteristic parameters as well as the critical value of damage variable were identified to provide a theoretical ground on which the plastic forming technology of magnesium alloy sheet can be optimized. The theoretical prediction was made with the numerical simulation program, and the results were verified by experiments. The forming limit curve of the theoretical prediction drawn by numerical simulation was established by the basic adaptation of the forming limit curve based on the experimental data.

Dynamic Test of Bird Strike on a Flat Plate Made from LY-12 Aluminium

2013 ◽  
Vol 765-767 ◽  
pp. 3158-3161
Author(s):  
Jun Liu ◽  
Zheng Li Zhang
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Dynamic Test ◽  
Time History ◽  
Aircraft Design ◽  
Bird Strike ◽  
Test Results ◽  
Valuable Data ◽  
Good Agreement ◽  
Peak Value

Tests of bird strike have been carried out on plate made from LY-12 Aluminium. The test was down with the projectile impacting the target perpendicularly at velocity of 40m/s, 80m/s, 120m/s respectively. The displacement-time history curves and strain-time history curves of on LY-12 Aluminium plate were measured. The good agreement of the results between two specimens in one group indicated that the results tested in the presnet paper are reliable. The dynamic response of the plate and damage modes of the bird influenced by striking velocity were analyzed. The peak value of the displacement linear enlarged with the increasing of the striking velocity. The test results in the present paper provided valuable data for aircraft design impacted by bird, and also provided abundant test datas for the numerical simulation model applied in bird striking.

Improved Formability and Deep Drawing of Cross-Rolled Magnesium Alloy Sheets at Elevated Temperatures

2005 ◽  
Vol 488-489 ◽  
pp. 461-464 ◽  
Author(s):  
Yong Chao Xu ◽  
Shi Hong Zhang ◽  
H.M. Liu ◽  
Z.T. Wang ◽  
W.T. Zheng ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Deep Drawing ◽  
Elevated Temperatures ◽  
Rolling Direction ◽  
Alloy Sheet ◽  
Rolled Sheet ◽  
Drawing Ratio ◽  
Cross Rolling ◽  
Magnesium Alloy Sheet ◽  
Cylindrical Cup

The extruded sheets were prepared at the temperature between 350ıand 400ı, and the magnesium alloy sheet was manufactured by a new method, cross rolling, in which the rolling direction was changed in each pass. At the time, deep drawing of magnesium alloy sheet was investigated at elevated temperatures. The results show that the sheet has refined-grain by cross-rolling after it was annealed at 250ı, and the formability is significantly improved at lower temperatures, which is superior to the extruded sheet and the one-way rolled sheet. Deep drawing of magnesium alloy was performed successfully, and cylindrical cup of limited drawing ratio (LDR) 2.6 and 35 mm deep rectangular box (65ı50) was achieved at the lower temperature of 170ı. The different types of fracture were analyzed and reasonable parameters were determined.

Forming Behaviour at Elevated Temperature of a Laser Heat-Treated AZ31 Magnesium Alloy Sheet

2018 ◽  
Vol 941 ◽  
pp. 1270-1275
Author(s):  
Donato Sorgente ◽  
Gianfranco Palumbo ◽  
Alessandro Fortunato ◽  
Alessandro Ascari ◽  
Ali Arslan Kaya
Keyword(s):  
Magnesium Alloy ◽  
Heat Input ◽  
Elevated Temperatures ◽  
Alloy Sheet ◽  
Az31 Magnesium Alloy ◽  
Dome Height ◽  
Magnesium Alloy Sheet ◽  
Laser Heat ◽  
Az31 Magnesium Alloy Sheet ◽  
Forming Behaviour

The tailoring of mechanical and technological properties of the initial material in sheet metal forming has been widely investigated and successfully applied. The benefits of such an approach can be found in the improvement of both the post-forming performances of the manufactured component and the forming process capabilities. Different strategies can be found and most of them involve a microstructural alteration by a selective heat source (e.g. laser, induction, UV light). The use of aluminium alloys combined with these strategies has been extensively investigated, while magnesium alloys are almost not yet considered from this viewpoint. In this work, we investigated the effect of a selective laser heat treatment on an AZ31 magnesium alloy sheet. After laser heat treating a single track in the centre of a blank with different heat input values, bulge tests at elevated temperatures were conducted. The dome height evolution was continuously acquired during the tests and differences between the untreated specimen and the laser treated ones have been characterized. The effect of the laser treatment was evaluated also in terms of thickness distribution of the formed specimens. A thickness discontinuity was found along the treated specimens in the transition zone between the treated and the untreated material. Results highlighted that an effective change in the forming behaviour can be induced in the treated zone depending on the laser heat input. It has thus been shown that this approach can be employed for tailoring the magnesium alloy blank properties prior to the gas forming at elevated temperatures.

Experimental Study on the Mechanical Property and Forming Limit of Magnesium Sheet at Elevated Temperatures

2009 ◽  
Author(s):  
Y. Huang ◽  
J. Huang ◽  
J. Cao
Keyword(s):  
Elevated Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Tensile Tests ◽  
Alloy Sheet ◽  
Dome Height ◽  
Forming Limit ◽  
Uniaxial Tensile ◽  
Magnesium Sheet

Magnesium alloy sheet has received increasing attention in automotive and aerospace industries. It is widely recognized that magnesium sheet has a poor formability at room temperature. While at elevated temperature, its formability can be dramatically improved. Most of work in the field has been working with the magnesium sheet after annealed around 350°C. In this paper, the as-received commercial magnesium sheet (AZ31B-H24) with thickness of 2mm has been experimentally studied without any special heat treatment. Uniaxial tensile tests at room temperature and elevated temperature were first conducted to have a better understanding of the material properties of magnesium sheet (AZ31B-H24). Then, limit dome height (LDH) tests were conducted to capture forming limits of magnesium sheet (AZ31B-H24) at elevated temperatures. An optical method has been introduced to obtain the stress-strain curve at elevated temperatures. Experimental results of the LDH tests were presented.

Numerical Simulation and Experimental Study of a Two-Floor Structure Pumping System

2010 ◽  
Author(s):  
Chao Liu ◽  
Yan Jin ◽  
Jiren Zhou ◽  
Fangping Tang
Keyword(s):  
Numerical Simulation ◽  
Simple Structure ◽  
High Efficiency ◽  
Test Results ◽  
Pumping System ◽  
Performance Curves ◽  
The Standard Model ◽  
Floor Structure ◽  
Low Efficiency ◽  
Good Agreement

The two-floor flow passages pumping system with the simple structure is well practical in the Basin of Yangzi River downstream. However, this kind of pumping system has some disadvantages, such as low efficiency, easy to appear submerse vortex in discharge flow passages which causes the unit vibration and does harm to the operating of pump unit. In order to solve these problems, the design scheme with a new curve of diffusing outlet structure and inlet cone put forward, which are used in the renovation of the two-floor flow passages pumping station. With the numerical simulation of the two-floor flow passages pumping system, the flow fields are analyzed, and the external performance curves are obtained. To verify the calculation, a model tests were done using the standard model of pump. The test results are compared with the performance curves of numerical simulation. Good agreement of two results is found in the high efficiency area, which can show the calculation is believable. The new design improves the efficiency of pumping system significantly and eliminates the submerse vortex, also can guarantees the economy and security of operating.

Forming limit analysis of Mg-2Zn-1.2Al-0.2Ca-0.2RE alloy sheet using ductile fracture models

2019 ◽  
Vol 29 (8) ◽  
pp. 1181-1198 ◽  
Author(s):  
Fei-Fan Li ◽  
Gang Fang ◽  
Ling-Yun Qian
Keyword(s):  
Magnesium Alloy ◽  
Ductile Fracture ◽  
Stress Triaxiality ◽  
Forming Limit Diagram ◽  
Alloy Sheet ◽  
Image Correlation ◽  
Forming Limit ◽  
Correlation Technique ◽  
Forming Limits ◽  
Fracture Models

This work was aimed to experimentally and theoretically investigate the formability of a new magnesium alloy sheet at room temperature. The fracture forming limit diagram was predicted by MMC3 and DF2014 models, where the non-linear strain path effect was taken into account by means of damage accumulation law. In order to obtain the instantaneous values of the stress triaxiality and the Lode parameter during the deformation process, strains tracked by digital image correlation technique were transformed into stresses based on the constitutive equations. The fracture forming limit diagram predicted by the fracture models was compared with the forming limits obtained by ball punch deformation tests. The prediction errors were evaluated by the accumulative damage values, which verified the advantages of ductile fracture models in predicting the forming limits of the magnesium alloy sheets.

Study on Formability about ME20M Magnesium Alloy Sheet

2010 ◽  
Vol 136 ◽  
pp. 23-27
Author(s):  
Ting Fang Zhang ◽  
Shi Kun Xie
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Deep Drawing ◽  
Material Model ◽  
Alloy Sheet ◽  
Simulation Software ◽  
Constitutive Relationship ◽  
Magnesium Alloy Sheet ◽  
Forming Temperature ◽  
Made In

Warm forming of magnesium alloy sheet has attracted more and more attention in recent years. Mechanics tension test has been made in this paper in order to study the constitutive relationship of ME20M magnesium alloy sheet at different temperatures and strain rates. And a constitutive relationship which includes a softening factor has been put forward. Warm deep drawing experiment and numerical simulation on ME20M magnesium alloy sheet have been made in which the attention was focused on the forming temperature. The results showed that the limit deep drawing height of ME20M magnesium alloy sheet can be dramatically improved as the temperature goes up, especially when the temperature was over about 250°C. Simultaneity, it is feasible and effective to add a material model into numerical simulation software by user subroutine.

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